Mine Surveying - Study Mode
[#106] The method in which stadia hairs are kept at fixed interval and the intercept on the levelling staff varies depending upon the horizontal distance between the instrument and staff called . . . . . . . .
Correct Answer
(C) Fixed hair
[#107] The purpose of providing a brass counter weight on one of the straight arms of circular disc of the compass is to . . . . . . . .
Correct Answer
(C) Balance the effect of dip of needle
[#108] Which types of surveys are to be adopted to fix the boundaries of enclosed lands
Correct Answer
(D) Cadastral surveys
[#109] Subsidary stations are joined by which lines . . . . . . . .
Correct Answer
(B) Tie lines
[#110] Hypotenusal allowance for a chain of 100 links measuring along a slope of 45° is . . . . . . . .
Correct Answer
(B) - 29.3 links
Explanation
Solution: Hypotenusal Allowance Explained: Imagine you're measuring a distance on a hill. A chain (used for measuring in surveying) measures accurately only on flat ground. If you measure along a slope, you'll measure a longer distance than the actual horizontal distance. Hypotenusal allowance corrects for this extra distance. It's the amount you need to subtract from your slope measurement to get the true horizontal distance. Think of a right-angled triangle: The slope distance is the hypotenuse. The horizontal distance is one shorter side. The angle is 45° in this question. Calculating Hypotenusal Allowance: Since the slope is 45°, the horizontal distance is less than the slope distance. The chain measures along the hypotenuse (slope), so we need to subtract (a negative allowance) to get the horizontal distance. The calculation involves trigonometry (which you'll learn later), but for now, just understand the concept. Therefore, the correct answer is the negative allowance. The calculation gives a value close to 29.3 links. Considering the other options, it becomes clear that you need to subtract this amount.